User-disposable polymeric foam members for placement within the auditory anatomy, such as the ear canal, of a user are useful to hold in place sound control devices, such as sound transmission and/or attenuation devices, and/or to attenuate unwanted sounds. Similarly, other earpieces for placement over the ear, on the ear, in the ear, or in the ear canal of a user may be used to attenuate sound.
Attenuation of sound energy utilizing viscoelastic polymeric foam may be achieved by various means. Some sound attenuation may be attributed to the mechanical properties of the foam. For instance, the tan delta of the foam is a property of the foam which is used to describe the ability of the polymer to dissipate energy. The tan delta is the ratio of two moduli of the foam called the storage modulus (G′) and the loss modulus (G″), thus tan delta=G″/G′. Certain structures produced in the foam can also enhance the sound attenuating capacity of the foam such as a surface skin which acts to reflect some of the sound energy before it enters the foam. Additives to the foam such as fillers of various types can provide reflecting surfaces to also reduce the transmission of sound energy. Another way that foam may attenuate sound energy is by the passage of the sound pressure waves through the pore openings into the individual cells of the foam. Energy is dissipated as the sound energy passes through the pores and enters the individual foam cells.
It is desirable to provide improved foam compositions for user-disposable members, and other earpiece members used as or with sound control devices including sound attenuation devices that have advantageous characteristics such as enhanced sound attenuation.